Heat Dissipating Device

ABSTRACT

A heat dissipating device includes an outer heat conducting unit, disposed with outer heat conducting plates, and an inner heat conducting unit. The outer heat conducting unit includes an outer surrounding wall having inner and outer wall surfaces. The inner wall surface defines a space. The outer surrounding wall further has an opening sealed by a cover. The inner heat conducting unit is formed as a separate component from the outer heat conducting unit, is received in the space, and is in thermal contact with the inner wall surface of the outer surrounding wall.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority of Taiwanese application no. 101208225, filed on May 2, 2012.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a heat dissipating device.

2. Description of the Related Art

Referring to FIG. 1, a heat dissipating device 1 according to R.O.C. patent no. M423992 is shown to include a heat conducting unit 11, a plurality of outer heat conducting plates 12 spacedly disposed on and formed integrally with the heat conducting unit 11, and a top cover 13 and a bottom cover 14 disposed on both ends of the heat conducting unit 11. The heat conducting unit 11 includes an inner surrounding wall 111, an outer surrounding wall 112, a plurality of plates 113 connected between the inner surrounding wall 111 and the outer surrounding wall 112, and a plurality of flow channels 114 cooperatively defined by the inner surrounding wall 111, the outer surrounding wall 112 and the plates 113. The top cover 13 and the bottom cover 14 seal both ends of the flow channels 114. Referring to FIG. 2, the top cover 13 has a top cover groove 131 and the bottom cover 14 has a bottom cover groove 141, and both grooves 131, 141 fluidly connect with the flow channels 114. As best shown in FIG. 2, when the heat dissipating device 1 contacts a heat source 100, the liquid coolant in the bottom cover groove 141 and in the flow channels 114 will absorb heat and turn gaseous, flowing upwards through the plurality of flow channels 114. Through the outer heat conducting plates 12, the heat in the gaseous coolant is dissipated and the coolant turns liquid, flowing downwards back to the bottom cover groove 141. Such cycle repeats to perform heat dissipation.

Due to the heat conducting unit 11 and the outer heat conducting plates 12 being formed integrally as a unit, they are commonly manufactured by aluminum extrusion or casting. However, when manufacturing by aluminum extrusion, the greater the number of the outer heat conducting plates 12 and plates 113, the greater will be the force a manufacturing machine needs to generate, and such high output manufacturing machine increases manufacturing costs. Also, the greater the number of the outer heat conducting plates 12 and plates 113, the higher frictional forces may also wear out the components in the manufacturing machine faster, decreasing the service life of the machines. When manufacturing by casting, the flow of material within a molding equipment and mold release may be affected due to the highly dense arrangements of the outer heat conducting plates 12 and plates 113, and manufacturing defects may result. Such drawbacks restrict the number of the outer heat conducting plates 12 and plates 113 that can be formed in the heat dissipating device 1 during manufacturing.

SUMMARY OF THE INVENTION

The object of the present invention is to provide a heat dissipating device that is relative to manufacture and that can effectively dissipate heat from a heat source.

According to the present invention, there is provided a heat dissipating device. The heat dissipating device includes an outer heat conducting unit which includes an outer surrounding wall having an inner wall surface and an outer wall surface. The inner wall surface defines a space. The outer surrounding wall further has a first opening. The outer heat conducting unit further includes a first cover to seal the first opening.

The heat dissipating device further includes a plurality of outer heat conducting plates spacedly disposed on and extending away from the outer wall surface.

The heat dissipating device further includes an inner heat conducting unit formed as a separate component from the outer heat conducting unit. The inner heat conducting unit is received in the space, and is in thermal contact with the inner wall surface of the surrounding wall.

BRIEF DESCRIPTION OF THE DRAWINGS

Other features and advantages of the present invention will become apparent in the following detailed description of the preferred embodiments with reference to the accompanying drawings, of which:

FIG. 1 is an exploded perspective view of a conventional heat dissipating device;

FIG. 2 is a sectional view of the conventional heat dissipating device;

FIG. 3 is an exploded perspective view of a heat dissipating device according to a first preferred embodiment of the present invention;

FIG. 4 is a schematic side view of the heat conducting unit according to the first preferred embodiment of the present invention;

FIG. 5 is a top view of the heat dissipating device, with a first cover removed according to the first preferred embodiment of the present invention;

FIG. 6 is a top view of the heat dissipating device illustrating a contact portion among the outer heat conducting plates according to a modification of the first preferred embodiment of the present invention;

FIG. 7 is a top view of the heat dissipating device, illustrating serrated surfaces, according to another modification of the first preferred embodiment of the present invention;

FIG. 8 is an exploded perspective view of the heat dissipating device, which further includes a second cover, according to yet another modification of the first preferred embodiment of the present invention;

FIG. 9 is an exploded perspective view of the heat dissipating device according to a second preferred embodiment of the present invention;

FIG. 10 is a top view of the heat dissipating device according to the second preferred embodiment of the present invention;

FIG. 11 is a top view of the heat dissipating device according to the second preferred embodiment of the present invention; and

FIG. 12 is a top view of the heat dissipating device according to a third preferred embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to FIGS. 3 and 4, the heat dissipating device 2 according to a first preferred embodiment of this invention includes an outer heat conducting unit 3, a plurality of outer heat conducting plates 41, and an inner heat conducting unit 5.

The outer heat conducting unit 3 includes an outer surrounding wall 31 and a first cover 32. The outer surrounding wall 31 has an inner wall surface 311, an outer wall surface 312, and a space 313 defined by the inner wall surface 311. The space 313 has a form of a blind hole and has a first opening 314. The first cover 32 seals the first opening 314. The outer heat conducting plates 41 are spacedly disposed on and extend away from the outer wall surface 312.

The inner heat conducting unit 5 is formed as a separate component from the outer heat conducting unit 3 and is received in the space 313. In this preferred embodiment, the inner heat conducting unit 5 includes an inner surrounding wall 51 corresponding in shape to the inner wall surface 311 of the outer surrounding wall 31, a plurality of inner heat conducting plates 52 spacedly disposed in and connected to the inner surrounding wall 51, and a plurality of flow channels 53 cooperatively defined by the inner surrounding wall 51 and the inner heat conducting plates 52. The flow channels 53 are defined by a plurality of surfaces 511. The inner surrounding wall 51 is welded to the inner wall surface 311 of the outer surrounding wall 31. The inner heat conducting plates 52 extend in a direction away from the first opening 314. The first cover 32 has a retaining portion 321 extending towards the inner heat conducting unit 5 and fittingly insertable into one of the flow channels 53. More than one retaining portion 321 may be provided to enhance retention of the first cover 32 on the inner heat conducting unit 5. Use of the retaining portion 321 is only one of many types of engagement applicable between the first cover 32 and the outer surrounding wall 31, and the invention should not be limited in this respect.

As illustrated in FIGS. 4 and 5, the outer wall surface 312 of the outer surrounding wall 31 has a contact portion 315, and the outer heat conducting plates 41 are disposed on a region of the outer wall surface 312 of the outer surrounding wall 31 other than the contact portion 315. When a heat source 9 contacts the contact portion 315, the coolant in the flow channels 53 absorbs the heat conducted from the heat source 9. After absorbing heat, the liquid coolant turns gaseous and moves upwards through the flow channels 53. The heat of the gaseous coolant is then conducted through the inner surrounding wall 51 and the outer surrounding wall 31 and is dissipated via the outer heat conducting plates 41. As the heat is dissipated, the gaseous coolant turns liquid and flows downwards through the flow channels 53 and is able to absorb heat again.

Referring to FIGS. 5 and 6, the size of the contact portion 315 can be modified according to needs. When the heat source 9 has a larger size, the contact portion 315 can have a larger area, and when the heat source 9 has a smaller size, the contact portion 315 can occupy a smaller area that allows for more outer heat conducting plates 41. Furthermore, as best shown in FIG. 7, surfaces 511 of the inner heat conducting unit 5 that define the flow channels 53 may be serrated surfaces such that the contact area between the coolant and the surfaces 511 is increased. Such increase in the contact area further improves the efficiency of heat dissipation.

Referring to FIG. 8, the outer surrounding wall 31 may further have a second opening 316 opposite to the first opening 314. The inner heat conducting plates 52 extend in a direction from the first opening 314 towards the second opening 316. The outer heat conducting unit 3 further includes a second cover 33 to seal the second opening 316. The second cover 33 has a retaining portion 331 that extends toward the inner heat conducting unit 5 and that is fittingly insertable into any one of the flow channels 53.

In this invention, the inner heat conducting unit 5 is formed as a separate component from the outer heat conducting unit 3. This effectively mitigates the problem of excessively large friction that arises when simultaneously forming the plurality of outer heat conducting plates 41 and the plurality of inner heat conducting plates 52 during aluminum extrusion in manufacturing, and the problem of uniformity in material flow during casting due to the highly dense arrangements of the plurality of outer heat conducting plates 41 and the plurality of inner heat conducting plates 52 in the molding equipment. By overcoming such problems, manufacturing costs can be effectively reduced and a greater number of the outer heat conducting plates 41 and the inner heat conducting plates 52 may be formed to increase the efficiency of heat dissipation.

Referring to FIGS. 9 and 10, the second preferred embodiment of the heat dissipating device 2 of this invention has several differences with the first preferred embodiment. A plurality of inner heat conducting plates 52 are spacedly disposed on the inner surrounding wall 51 and connect the inner surrounding wall 51 with the outer surrounding wall 31. The inner surrounding wall 51 and the inner heat conducting plates 52 cooperate with the outer surrounding wall 31 to define a plurality of flow channels 53. During assembly, the inner heat conducting unit 5 is placed into the space 313 of the outer surrounding wall 31, and then the inner heat conducting plates 52 are welded to the inner wall surface 311 of the outer surrounding wall 31. In this preferred embodiment, the retaining portion 321 of the first cover 32 and the retaining portion 331 of the second cover 33 are both fittingly engaged with the inner surrounding wall 51. The shape of this preferred embodiment that is different from the first embodiment can be modified to suit different needs. As illustrated in FIG. 11, the plurality of outer heat conducting plates 41 and the plurality of inner heat conducting plates 52 may be manufactured in the form of curve shapes to improve the efficiency of heat dissipation.

Referring to FIG. 12, the third preferred embodiment of the heat dissipating device 2 of this invention has several differences with the second preferred embodiment. The inner heat conducting unit 5 further includes a surrounding plate 54 surrounding and connected to the inner heat conducting plates 52. The plurality of flow channels 53 are cooperatively defined by the inner surrounding wall 51, the surrounding plate 54 and the inner heat conducting plates 52. The surrounding plate 54 is welded to the inner wall surface 311 of the outer surrounding wall 31. With the surrounding plate 54, the increased contact area between the inner heat conducting unit 5 and the inner wall surface 311 of the outer surrounding wall 31 improves fitting engagement between the inner heat conducting unit 5 and the outer surrounding wall 31.

In summary, the heat dissipating device 2, by separating the inner heat conducting unit 5 and the outer heat conducting unit 3, effectively mitigates the problem of excessively large friction and the problem of material uniformity during casting. By such, the manufacturing costs can be effectively reduced and a greater number of the outer heat conducting plates 41 and the inner heat conducting plates 52 may be formed to increase the efficiency of heat dissipation.

While the present invention has been described in connection with what are considered the most practical and preferred embodiments, it is understood that this invention is not limited to the disclosed embodiments but is intended to cover various arrangements included within the spirit and scope of the broadest interpretation so as to encompass all suchmodifications and equivalent arrangements. 

What is claimed is:
 1. A heat dissipating device comprising: an outer heat conducting unit including an outer surrounding wall having an inner wall surface and an outer wall surface, said inner wall surface defining a space, said outer surrounding wall further having a first opening, said outer heat conducting unit further including a first cover 32 to seal said first opening; a plurality of outer heat conducting plates spacedly disposed on and extending away from said outer wall surface; and an inner heat conducting unit formed as a separate component from said outer heat conducting unit, received in said space, and in thermal contact with said inner wall surface of said surrounding wall.
 2. The heat dissipating device as claimed in claim 1, wherein said first cover has a retaining portion extending towards said inner heat conducting unit.
 3. The heat dissipating device as claimed in claim 1, wherein said inner heat conducting unit includes an inner surrounding wall corresponding in shape to said inner wall surface of said outer surrounding wall, a plurality of inner heat conducting plates spacedly disposed in and connected to said inner surrounding wall, and a plurality of flow channels cooperatively defined by said inner surrounding wall and said inner heat conducting plates; said inner surrounding wall being welded to said inner wall surface of said outer surrounding wall, and said inner heat conducting plates extending in a direction away from said first cover.
 4. The heat dissipating device as claimed in claim 3, wherein said space of said outer heat conducting unit has a form of a blind hole.
 5. The heat dissipating device as claimed in claim 3, wherein said outer surrounding wall further has a second opening opposite to said first opening, said outer heat conducting unit further including a second cover to seal said second opening, said inner heat conducting plates extending in a direction from said first opening towards said second opening, said second cover having a retaining portion extending toward said inner heat conducting unit.
 6. The heat dissipating device as claimed in claim 3, wherein said outer wall surface of said outer surrounding wall has a contact portion for contacting a heat source, said outer heat conducting plates being disposed on a region of said outer wall surface of said outer surrounding wall other than said contact portion.
 7. The heat dissipating device as claimed in claim 3, wherein said inner heat conducting unit has surfaces that define said flow channels and that are serrated surfaces.
 8. The heat dissipating device as claimed in claim 1, wherein said inner heat conducting unit includes an inner surrounding wall, and a plurality of inner heat conducting plates spacedly disposed on said inner surrounding wall and welded to said outer surrounding wall, said inner heat conducting plates extending in a direction away from said first cover, said inner surrounding wall and said inner heat conducting plates cooperating with said outer surrounding wall to define a plurality of flow channels.
 9. The heat dissipating device as claimed in claim 8, wherein at least one of said outer heat conducting plates and said inner heat conducting plates is a curved plate.
 10. The heat dissipating device as claimed in claim 1, wherein said inner heat conducting unit includes an inner surrounding wall, a plurality of inner heat conducting plates spacedly disposed on said inner surrounding wall and extending towards said outer surrounding wall, a surrounding plate surrounding and connected to said inner heat conducting plates, and a plurality of flow channels cooperatively defined by said inner surrounding wall, said surrounding plate and said inner heat conducting plates; said surrounding plate corresponding in shape to said inner wall surface of said outer surrounding wall and being welded to said inner wall surface of said outer surrounding wall, and said inner heat conducting plates extending in a direction away from said first cover.
 11. The heat dissipating device as claimed in claim 10, wherein at least one of said outer heat conducting plates and said inner heat conducting plates is a curved plate. 